The production of a poly(ester carbonate) from monomers such as bisphenol A, terephthaloyl chloride and phosgene is described in U.S. Pat. Nos. 4,156,069 of Prevorsek et al. and 4,194,038 of Baker et al. In U.S. Pat. Nos. 4,194,038 and 4,129,594, the terephthaloyl chloride, or similar acid chloride, is synthesized from the corresponding aromatic or cycloaliphatic acid by reaction with phosgene in organic solution. Thereafter, in U.S. Pat. No. 4,194,038, phosgene and a dihydric aromatic alcohol such as bisphenol A are added in a prescribed manner to the solution to produce the poly(ester carbonate). Accordingly, the process of U.S. Pat. No. 4,194,038 provides for the production of the poly(ester carbonate) from the aromatic or cycloaliphatic dicarboxylic acid without isolation or the acid chloride by solution processes in a single reaction chamber.
For various reasons, it is often desirable commercially to produce condensation polymers such as polyesters and poly(ester carbonates) by an interfacial process in which the bisphenol is introduced as an aqueous solution of the corresponding alkali metal salt. Such an interfacial process is described in copending, commonly assigned U.S. Pat. application Ser. No. 29,422 of Segal et al., field Apr. 12, 1979 now U.S. Pat. No. 4,255,556 (1981), proceeding from the acid chloride such as terephthaloyl chloride as the reactant. Terephthaloyl chloride is introduced in relatively pure form, and no consideration is given in the disclosure of this copending application to complications due to the presence of catalysts or by-products from the production of the acid chloride. It would be desirable to produce poly(ester carbonates) by an interfacial process in a single reaction chamber or, at least, to produce same from the aromatic or cycloaliphatic acid chloride without isolation or extensive purification of the acid chloride from catalysts or by-products of its synthesis.